Edit Cars Model

Hello I do not know how to open the file 3d model: cars_highLOD.pssg
What program to use to edit the model??
I use 3dsimEditor. I isolate nose but I do not know how to save it after editing the format cars_highLOD.pssghttp://fotofotki.pl/pliki_img/dtmo3ymnqbp6jnew6w0i.jpg